This invention relates to a fluid line swivel-joint connector having a quick-disconnectable coupling for uncoupling and shutting flow of the fluid through the line, and more particularly to a swivel joint connector for mounting in a fuel supply line of a fuel dispensing station for communicating a first fluid conduit rotatable about a first axis at one end to a second fluid conduit rotatable about a second axis at the other end so that a rigid conduit connected to one end may swivel relative to a flexible conduit connected to the other end, the connector having detachable means permitting uncoupling to shut flow communication at the joint when the tensile load at the joint is above a predetermined level, and being adapted to align the longitudinal axis of the end connected to the flexible conduit with the direction of any tensile force applied therethrough, the connector additionally having a releasable bearing member for supporting bending loads prior to alignment. The swivel joint may be mounted in a fuel line of a fuel dispensing station to permit a dispensing nozzle to pivot relatively to a fuel supplying hose, or it may permit the hose to pivot relatively to a rigid section of the fuel line.
It is known in the fuel dispensing art to include a swivel connector at the dispenser/hose interface so that twisting loads applied to the dispenser are not transmitted to the hose resulting in twisting thereof. Such swivels merely permit the dispenser, such as a fuel dispensing nozzle, to be pivoted about one or more axes relative to the axis of the hose, the swivel permitting flow communication means between the hose and the dispensing device.
Additionally, it is known to utilize quick disconnect or breakaway couplings in the fuel line spaced from the dispenser so that if a vehicle is driven away from the fuel dispensing station before the dispensing nozzle is removed from the filler neck of the vehicle, an uncoupling will result, shutting the flow of fuel and preventing the volatile fuel to be spilled due to either a dislodging of the moorings of the fuel dispensing station, breakage of the hose, or other failure of the fuel dispensing system. The prior art has proposed a number of decouplers which are actuated by a tensile force in the line.
In U.S. Pat. No. 4,779,638 of Nitzberg et al, the problems and deficiencies of the prior art decoupler units was described including that of premature uncoupling, snap decoupling, and the cumulative affect of tensile force on the line and the hydrostatic forces of the liquid within the coupling, and combination swivel-joint and quick-disconnect coupling devices are disclosed that substantially overcome these problems. The devices there have coupling means between first and second body members which swivel relatively to one another and the coupling means normally acts to connect the body members in flow communication and to decouple when an external tensile force above a predetermined level is applied to the fuel line, and include valving acting for shutting flow communication when the body members are decoupled.
There are, however, certain occasions wherein the direction of the external tensile force applied to the fuel line is such that both in conventional swivel connectors and in the combination swivel-joint quick-disconnect couplings or connectors disclosed in the aforesaid U.S. Patent where the tensile force will not permit the swivel-joint to pivot, i.e, the reaction force to the external tensile force does not act in a direction which effects rotation about the pivot axis. Such conditions may occur when a swivel-joint having one end connected to a flexible fluid conduit, such as a hose, and another end connected to a rigid fluid conduit, such as a nozzle or rigidly mounted piping, does not permit the end connected to the flexible conduit to align itself with the direction in which the tensile force is applied. When this occurs a bending moment results which may act to shear the interconnecting members of the joint. For example, if the external tensile force is applied in the same plane as that of the pivot axis of the swivel joint and of the axes of the inlet and outlet to the swivel joint, the reaction to that force can only be resisted by the interconnecting members of the joint, and if the force is substantial a shearing of the elements may occur. In U.S. Pat. No. 4,791,961 of Nitzberg et al a swivel-joint coupling was disclosed which overcomes this problem by providing a two-axis swivel coupling having the longitudinal axis of the swivel joint and the end thereof connected to the flexible conduit offset relative to a plane parallel to one of the swivel axes and passing through the other so that the coupling could align the longitudinal axis of the end connected to the flexible conduit with the direction of any tensile force applied through the flexible conduit. Therefore, the longitudinal axis at the connecting member with the flexible conduit was disposed such that it is always offset from that plane which passes through the first swivel axis and is parallel to the second swivel axis.
Although, the apparatus of the aforesaid Nitzberg et al U.S Pat. No. 4,791,961 overcomes the problem of potential shearing of the interconnecting members of the joint so that the force applied to the flexible conduit is resisted without a reaction force tending to pull or pry apart the swivel connection by permitting alignment of the end connected to the flexible conduit with the direction in which the tensile force is applied, until such alignment occurs the interconnecting members resist the load. The interaction of the forces on the interconnecting members results in wear, and after a period of time the cumulative affect can result in breakage of the interconnecting elements.